These are outstanding headphones as far as I'm concerned. Before these I stuck primarily with IEMs but now I have seen the light. I've tried other headphones but they've never been this comfortable, especially when wearing glasses. These are like clouds on my head. So comfortable! They were a little tight out of the box but I carefully adjusted the bend of the metal arms to get the firmness just right. The included cable is nice quality, it isn't sticky rubber, and is a perfect length for desk use.
Sound quality is excellent. The sound is fairly neutral with nice bass without being overwhelming. The sound stage seems good to me as far as open back headphones go and I've run some specific audio tracks to test this. These are very easy to drive, and while they benefit from an amplifier in most circumstances, they can still be used with most phones and DAPs. I believe the impedance is 150 ohms.
I highly recommend these headphones. They're an excellent deal for the price.